Method and means for making castings



March l, 1938.

E, G. GRUNDSTRQM METHOD AND MEANS FOR MAKINGv CASTINGS Filed July l0, 1937 .Patented Mar. l, 1938 PATENT oFFlcE Mn'mon AND MEANS Fon MAKING.

' cAs'rmGs Erik G. Grundstrom, Chicago, Ill., assiguor to Advance Aluminum Castings Corp., Chicago, Ill., a corporation of Illinois Application my 1o, 1931,'seria1'Nb. 152,882

.3 Claims.

The present invention relates to methods and means for making castings.

In making certain castings, particularly those having long, relatively thin sections, it has been 5 difficult to maintain the molten metal in pure condition as it enters the mold and to obtain a perfect `casting. countered to a very considerable extentin making castings of aluminum or aluminum alloys; the

,10 dross having a tendency to enter the mold cavity.

An object of the present invention is to provide improved-apparatus for making castings, particularly for making castings of aluminum or alloys thereof.

A further object is to-provi'de an improved method for making castings in whichdross, oxides and the like are prevented from entering the mold cavity.

Further objects will appear as the description proceeds.

Referring to the drawing- Figure 1 is a sectional view of a two-part mold embodying the principles of the vpresent invention, said gure being taken along the plane indicated by the arrows I-I of Figure 2;

Figure 2 is a view taken along the plane indicated bythe arrows 2-2 of Figure 1, half of the mold beingremoved; and

Figure 3 is a sectional view taken alongthe plane indicated by the arrows 3 3 of Figure 1.

A two-partmold of the permanent mold type is illustrated in the drawing. Said mold lncludes thetwo cooperating mold parts I0 and I I said mold parts having cooperating faces to mold a casting such as indicated by the numeral I2.

The particular casting chosen for illustration isthe head of the motor of an internal combustion engine. y Said casting is long and rather wide but 40 relativelythin inmost of its cross section. Many difficulties have been encountered in the past in making such a casting due to the fact that the molten aluminum or aluminum alloy `must under usual practical conditions drop through a con- Y siderable distance, collecting air and forming parts Iii and II. Said'l mold parts are formed 'to provide a gate, indicated by the numeral I l, which gate is an elongated cavity. As the parts 55 are used, the long axis of this gate .Il will pref- This diillculty has beenen 'megane la. r 'steel or other material which will not be attacked erably be vertically disposed. T'he two parts I0 and II/oi the mold are provided with grooves for the reception of a strainer, indicated by the numeral I5. Said strainer is an elongated member provided with holes I6 throughout the great- 5 er part'of its length. The upper extremity of the strainer I5 isbent over to provide a hand hold Il. Adjacent to the gate II is the inlet passage I8, through whichmolten aluminum or the like can be admitted to the gate Il. Said 10 passage I8 and gate I4 have communication with -one another adjacent to the lower extremity of said gate I4, the lower extremities of the gate I l and the passageway 'I8 being connected by the passageway I8. Cross passageways 2li-20 may l5 be provided at various levels for the purpose of admitting molten metal at various heights along The strainer I5 4may be made of ity I3.. As molten aluminum or the like is poured 25 l into the passage I8, said molten metal will rise in the gate Il land will be strained through the 'strainer I5 into the mold cavity I3. The dross,

or the like, which may form in the molten -aluminum will be held back byv said strainer I5 and 30 only the pure metal will pass through the holes I6 into the mold cavity I3.l

After the mold cavity has been filled and while the molten metal is quiescent and before the aluminumhas solidified, the strainer I5 will be with- 35 drawn.` I'As the casting within the mold cavity I3 solidifies and shrinks inthe solidifying process, metal will be drawn into said mold cavity from the gate I4 to compensate for said shrinkage, the necessary free access being had by reason of the withdrawal of the strainer I5.

Many modifications of the present invention will occur to those skilled in the art. It is intended to cover allsuch modicatlons that fall'45 within the scope of theappendedclaims.

1. In a permanent mold, -in combination, co-

j operating mold parts dening a mold cavity, said mold parts dening a passageway comprising a `l0 said mold cavity, said strainer being removable when said mold parts are in cooperative relationship with each other.

3. The method of making a casting which consists of admitting molten metal to a mold cavity through a strainer, permitting .said strainer to remain in cooperative relationshiprwith said mold cavity until the metal in said mold cavity is quiescent, and thereafter removing said strainer before said metal has solidified.

' -ERIK G. GRUNDSTROM. 

